Lubbock wastewater
project shows
improvement

Published: Wednesday, June 04, 2008

ELLIOTT BLACKBURN

Contamination problems that have residents purchasing bottled water for homes and businesses east of Lubbock have reached their lowest levels in nearly a decade, according to the most recent report filed with state environmental regulators.

It was too soon to credit changes made last fall to the Lubbock Land Application Site, including an end to cattle grazing on the property and a shift in the crops used in the program, though officials believed the changes helped.

Nitrate levels in groundwater beneath the property remain well above federal drinking water standards, however, and a separate report on a similar project outside Wilson suggested Lubbock water officials still have work to do.

"What we're finding right now is that we're at that balance, we're in good shape," said Assistant City Water Manager Aubrey Spear. "We just couldn't afford to put any more out there."

The city disposes nearly two-thirds of the 20 million gallons of wastewater Lubbock produces each day through land application sites. The city uses crops not fit for human consumption to soak up the nitrogen in the treated wastewater.

In theory, the system balances out the lingering pollutants in the treated wastewater. But decades of poor practices led to a huge dome of contaminated water beneath 5,100 acres of city-owned property outside East Loop 289.

Water beneath the Lubbock site contained nitrate levels of 16 milligrams per liter, down from 16.49 milligrams per liter recorded a year ago.

It was the closest the average level of nitrates from wells across the property had come to the federal maximum of 10 milligrams per liter since 1999, according to a report prepared for the city and submitted to the Texas Commission on Environmental Quality on Friday.

Water levels beneath the property also continued to fall. Too much water pushed onto the property over the years created a huge dome of water underneath the land, spreading the contamination. The nitrate-laced groundwater should begin draining back toward pumps on the property within the next few years if levels continue to fall.

Farm managers adjusted practices at that site last fall. Officials phased out a cattle grazing program that seemed to keep the nitrates in place and adjusted the mix of plants grown on the property.

It was too soon to credit the changes with the lower levels, but the site made good progress, wastewater environmental compliance officer J.D. Booker said.

"We continue to better our operations and refine the balance out there between the effluent and the removal by the crops," Booker said.

Officials hope to hold the line at the Lubbock site until the city can complete major renovations to the wastewater plant that will improve the quality of treated water.

The better water, still years away, will help flush out the nitrates under the site, Spear said.

"It is something that takes a long time to clean up, so it's not going to happen in the next 10 years," Spear said.

Nitrate levels increased slightly at the city's other land application site outside the city of Wilson. Water in several of the wells, including at least one near groundwater pumped by Wilson for residents, moved out of federal drinking water compliance and into their highest recorded concentration of nitrates.

Lubbock was watching the wells and working with Wilson, but Booker said the nitrate levels tended to fluctuate in that area.

"If we see this again, we may be thinking there's a movement toward the high end," Booker said. "But we believe they're just in their natural variability that we've seen over their history."